Abstract: A process and apparatus for drying pastes, liquors and aggregate materials by means of a heat integrated and/or heat pumping process and/or apparatus is disclosed. This includes a heat pump or heat integrated apparatus operable in a drying apparatus with the heat pump evaporator (36) or cold heat exchanger in primary thermal contact with the drying gas medium (33) after said drying gas medium (33) has taken up moisture from the material being dried (35) and the heat pump condenser (14) or hot heat exchanger (36) in primary thermal contact with the material being dried and with both the drying gas medium (33) and any heat pump refrigerant in nominally closed loop circulation paths (22). This process and apparatus may provide improved efficiency and reduced costs by reducing the required flow of drying gas through the system since that drying gas is no longer the primary means for supplying heat to the material being dried.

Abstract: An apparatus and process including a heat sink exchanger (26) to cool and condense liquid out of a drying gas with a heat transfer surface arranged to exchange heat with a first sub-stream of the drying gas and a heat source heat exchanger (27) arranged to exchange heat with a second sub-stream of a drying gas and arranged in a functionally parallel configuration with said heat sink heat exchanger (26) so that each of said drying gas sub-streams exchanges heat with one of the two said heat transfer surface per cycle through the heat exchange system and a gas movement device (35) for propelling the drying gas through the heat exchanger system in either a forward or reverse flow path direction.